The present invention relates to a device and method for displaying text on a screen. More particularly, the present invention relates to a device and method for displaying the text of an electronic document on a screen for reading by a user in real time.
Present-day computer monitors are generally configured to present textual information in a manner that replicates the central features of the more traditional form of communicating by way of the printed word on paper. For example, in many cases, when reading an electronic document on a computer screen, the information is generally presented in a fashion intended to resemble the reading of a page of a book, report or other printed document. Although there are some similarities between printed and electronically-displayed documents, there are many differences.
In traditional documents printed on paper, the storage media for the document is the text inscribed or written on the reflective surface of the paper. The storage media--the paper--also serves as the display media. In other words, writing the textual information onto the paper simultaneously imparts and fixes the display characteristics of the document to be presented to a subsequent reader. Accordingly, the legibility of the text is fixed by the author or printing process at the time the text is written onto the paper. In the case of paper documents, the author/printer of the document (and not the reader) has complete control over the display characteristics of the text (i.e., the legibility). In other words, the page layout, the font type, size and other legibility characteristics of the document cannot be altered by the ultimate reader of the text. In addition, each reader of the text is confronted with the same display which cannot be tailored or optimized to his or her personal preferences.
In contrast, in the case of electronic documents displayed on a computer screen, the legibility of the text is separated both logically and functionally from the storage media. In other words, the legibility is no longer controlled by the original author of the document, but by some outside source or other factors. Although the user of a computer or other electronic system generally has some degree of control over the display of the text, such systems can place several obstacles in front of the person who desires to read the text of an electronic document in a manner most convenient for that person.
In particular, a computer monitor itself can create problems in reading an electronic document. These problems can include poor edge and character contrast of the displayed text, a display surface which is not flat in the case of CRT screens, font types and sizes which are translations of fonts initially designed and optimized for reading from a reflected surface such as paper but not an irradiated one as in the case of computer monitors. Additional problems in reading text from computer monitors arise due to the height to width ratio of the monitor. For printed documents, the height of the document is generally the larger of the two dimensions. In the case of computer monitors, the inverse is usually true: the width (and not the height) of the monitor is generally the larger of the two dimensions. While these problems cannot normally be addressed unless the monitor is redesigned, their negative impact on legibility can be magnified by the software programs being used to control the monitor.
Methods of presenting text to computer monitors by software generally fall into two basic approaches: character-based and graphical user interface-based, the later of which is more widely used in present-day computer monitors. Graphical user interfaces present further obstacles to legibility in displaying electronic documents on a computer monitor. Such graphical user interfaces frequently will provide color and shading in an attempt to present the reader with the illusion of a multidimensional space as encountered when reading text on a printed page. However, that illusion is not perfect.
This multidimensional space is typically presented to the user as though the surface is that of one or more sheets of paper on a desktop. This presentation is generally intended to "trick" the user into believing the text is being displayed on a printed page. The actual surface is an electrically charged chemical applied to the opposite side of a sheet of glass. Though the use of shading and other techniques does present a credible version of a multiple dimensional reality, the fact that it is an illusion being projected on the far side of the screen is always readily apparent through the glare of ambient light on the actual glass surface. This duality of reflected versus projected light on the screen significantly impairs the legibility of the text displayed through this illusion. A demonstration of the significance of this problem is the size of the industry devoted to the manufacture of glare shields and guards for computer monitors. The primary impact of this problem on the user is most evident when attempting to read for comprehension of non-trivial information from a large body of text.
Further complicating and degrading the legibility of graphical user interface-based displays is relates to a fundamental assumption upon which such interfaces are built: that the final product of the electronic document will be a version printed to paper. This is a key factor affecting legibility as it clearly places the emphasis on a printed version of the material. In this sense, the computer industry has focused on the legibility factors affecting the memorialization of a document after it has been printed on paper and generally not on legibility factors affecting the presentation of the text on the computer monitor itself. The computer monitor in this sense has been considered merely a place to manipulate the text of an electronic document for final printout to paper.
Accordingly, computer monitors generally target their font type and size to the final document printed on paper. True font sizes and typeface reproduction are not created on the monitor but rather only after printing on the printed paper. The screen representations of the typeface are generally not "to scale" but are intended to mock-up the printed output within the framework of the computer monitor's height to width aspect ratio. This mock-up generally uses a translation algorithm which alters all aspects of the displayed text including perceived character height, the line spacing and the aspect ratio of the typeface ascendants and descendants. This is done to make the characters look as near as possible like the paper-printed copy. In fact, this philosophy of software design is widely touted as WYSIWYG ("What You See Is What You Get"). In fact, some manufacturers of graphical user interface displays even employ claims of "accurate" reproduction of paper and page displays as selling points for their respective products.
Further problems with reading text from computer monitors are presented by the software being used by the computer at the so-called "application" level. Programs such as word processors, spreadsheets, or database management software, or project management software, or electronic mail are focused on the creation of text, or its retrieval for editing rather than its presentation for display on the computer monitor. These programs have generally adopted a "page" format. This is to say that these programs present their displays as though they were printing the information on a sheet of paper pasted to the inside of the computer monitor. In using this page paradigm on today's computer monitors, software programs typically provide some form of scrolling to access the hidden parts of the text of a page that cannot be shown on the screen due to the size limitations forced on the display by the aspect ratio of the monitor. This scrolling (either in the horizontal or vertical directions) can place serious constraints on the reader's access to the text by imposing delays as the chosen part of the page is scrolled into view. Further reading speed and comprehension problems can be caused by the shift in focus to the control mechanisms of the software rather than reading the displayed text.
The overall effect of all of the above problems on the final legibility of displayed text is that the average reading speed of the user will be slower in reading an electronic document than reading a printed document. In addition, the comprehension level of the reader will be lower than when reading the corresponding material from paper. There will also be more physical energy expended by the reader in reading from the computer screen. Further effects include a rise in eye, neck and facial muscle tension as the reader attempts to compensate for the poor presentation and legibility of the electronic document.
The conventional display of electronic documents on a computer monitor also presents severe obstacles to readers with disabilities, either perceptual, cognitive or physical. In the case of a reader who is paralyzed, the energy required to manipulate the complex scrolling involved is often debilitating. Additionally, persons with visual impairments will have difficulty in customizing the display of traditional software programs to a level that is legible to that particular person. And as font size is increased in displaying electronic documents, the reading speed generally decreases due to the increased intrusion of complex scrolling.
In addition to the above, the display of text on computer monitors can present some obstacles to effective reading in areas such as manufacturing sites where the environment can be considered dirty for reading purposes. This would include any site with local pollution to the point that general atmospheric refraction of light is increased above an acceptable level to make it difficult to discern the text on a screen, or where particulate material accumulates on a screen to a level of obscuring too many pixels.
In order to address some of the above problems associated with the display of text from an electronic document on a screen, there has been a prior attempt to fundamentally alter the manner in which the text is displayed. In particular, a method has been proposed whereby the text of an electronic document is displayed on a computer monitor one word at a time. A microprocessor is used to automatically and sequentially update the one-word screen with the next word in the document so that the user would not be distracted with scrolling. This method would allow the user to pay full attention to the words being displayed on the one-word monitor.
A problem encountered with the above proposed method for displaying text is that with today's conventional desk- and lap-top computer systems, the interaction of the operating software with the computer hardware was such that real-time control of the display process could not achieved efficiently. In particular, since conventional software control of desk- and lap-top computers is achieved using sequential processing, the computer monitor could not be updated fast enough, without interruption at high display speeds, if it was desired to be able to allow the reader of the document to simultaneously control the legibility characteristics of the text (i.e., font type, size, color, display speed, etc.). As this inventor has now determined, as will be explained below, this deficiency of the prior art was due to the fact that in order for such a system to work, the microprocessor must perform three separate functions simultaneously: (1) it must continuously read into memory the relevant portions of the subject document from a storage device, (2) it must constantly update the one-word screen with the next word in the document, and (3) it must react to and keep track of a user's desired legibility characteristics entered through a keyboard.
Using conventional software control of today's desk- and lap-top computers, the prior art could not provide a display device that was capable of uninterrupted, one-word display of an electronic document while at the same time being able to allow the reader of the document to simultaneously control the legibility characteristics of the text in real time.
In light of the above, it would be desirable to be able to provide a device and method for the efficient and convenient display of the text of an electronic document on a screen one word at a time.
It would also be desirable to be able to provide a device and method for uninterrupted, one-word display of an electronic document being able to allow the reader of the document to simultaneously control the legibility characteristics of the text in real time.
It would further be desirable to be able to provide a device and method for displaying the text of an electronic document one word at a time using a low-cost processor for controlling the reading and displaying of the document.